Problem: $ { \left[\begin{array}{rr}{-2} & {-2} \\ {-1} & {-1} \\ {4} & {3}\end{array}\right]+\left[\begin{array}{rr}{3} & {1} \\ {4} & {-1} \\ {0} & {3}\end{array}\right] = {?} } $
To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rr}{-2}+{3} & {-2}+{1} \\ {-1}+{4} & {-1}+{-1} \\ {4}+{0} & {3}+{3}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{1} & {-1} \\ {3} & {-2} \\ {4} & {6}\end{array}\right]}$